Biosimilar switching and related medical liability.

Unlike generics, biosimilars are similar, but not equivalent, to the reference biological medicinal product. Therefore, if a patient experiences an adverse event, or a loss of efficacy, when transitioned to a biosimilar, the distribution of medical liability will be different from the case of both the originator and generics. Moreover, the case of naïve patients is different from that of non-naïve patients. In the case of naïve patients, physicians make their choice from a range of medicinal products that pose the same risk, since it is not possible to know with any certainty the patients' response to each therapeutic option until they have taken the drug. If physicians, instead, switch to a biosimilar for a patient already in treatment with the originator, they are switching from an option where the individual response is known, to an option where it is unknown. Given the evolving framework of biosimilar legislation, sharing choices with patients and obtaining their informed consent when switching to a biosimilar could represent an effective approach on the part of the prescribing physician. Moreover, a supranational database containing real-life data about patients in treatment with biological medicines, including information on the actual biological medicinal products administered, could complement the data obtained from clinical studies.